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Journal of Forestry Research 2006年第3期17卷 252-254页

作者： WANG Qing-gui XING Ya-juan ZHOU Xiao-feng HAN Shi-jie Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 P.R. China Heilongjiang University Harbin 150080 P.R. China Northeast Forestry University Harbin 150040 P.R. China

Twenty-three secondary forest communities with different structure were selected in Mao＇er Mountain National Park of Heilongjiang Province, China to study the relationship between diversity of forest plant species and environmental gradient. The forest plant species diversity was analyzed by the diversity index, and the environmental factors was quantified by the method of Whittaker＇s quantification of environmental gradient. Meanwhile, β-diversity indexes of communities were calculated with similar measurements. The results showed that the Shannon-wiener diversity index of forest plant species increased with the increase of the environmental gradient, and the β-diversity indexes of communities showed a liner increase along with the change of environmental gradient.

关键词： Species diversity Forest plant species Heilongjiang Province Shannon-wiener diversity β-diversity index environmental gradient

Spatial distribution patterns of wetland plants in relation to environmental gradient in the Honghe National Nature Reserve, Northeast China

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Journal of Geographical Sciences 2012年第1期22卷 57-70页

作者： ZHOU Demin LUAN Zhaoqing GUO Xiaoyu LOU Yanjing Key Lab of Wetland Ecology and Environment Northeast Institute of Geography and Agricultural Ecology CAS Institute of Water Resources and Environment Jilin University College of Resources Environment and GIS Capital Normal University

Quantifying correlation between the spatial patterns of natural wetland plants and environmental gradient gives better understanding of wetland habitats, which is the fundamental for the strategy making on the protection and restoration of natural wetlands. In this study, the spatial patterns of wetland plants and the environmental gradient of wetland habitats were assessed in the Honghe National Nature Reserve （HNNR） in Northeast China, a wetland of international importance on the Ramsar list. Biophysical parameters’ values of wetland plants were obtained by field sampling methods, and wetland mapping at the community scale was completed using remote sensing techniques. Digital delineation of the surface water system, hydrological zoning and wetness index were produced by spatial analysis methods in Geographic Information System. An ecological ordination method and two clustering methods were used to quantify the relationship between the spatial distribution patterns of wetland plants and the corresponding environmental gradients. Such quantitative analyses also present the specific diversity of different types of wetland plants based on the environmental attributes of their habitats. With the support from modern geo-information techniques, the experimental results indicate how four ecotypes of wetland plants spatially transit from forest swamp, shrub wetland and meadow into marsh wetland with increasing wetness index and water table. And they also show how wetland spatial distribution patterns are controlled by an environmental gradient of wetness. Another key finding of this research work is that our results present the exact fundamental differences between marsh and non-marsh plants of 11 wetland plant communities within the core study area. Hence, this case study gives a good sample for better understanding of the complex correlation between the spatial patterns of wetland plants and their environmental attributes using advanced digital analysis methods. It is

关键词： wetland plant ecology spatial pattern environmental gradient Honghe National Nature Reserve

Floristic composition and structure of the Kibate Forest along environmental gradients in Wonchi,Southwestern Ethiopia

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Journal of Forestry Research 2021年第6期32卷 2669-2682页

作者： Misganaw Meragiaw Zerihun Woldu Vegard Martinsen Bal R.Singh Department of Plant Biology and Biodiversity Management College of Natural and Computational SciencesAddis Ababa UniversityNational HerbariumP.O.Box 3434Addis AbabaEthiopia Faculty of environmental Sciences and Natural Resource Management Norwegian University of Life SciencesP.O.Box 50031432ÅsNorway

Dry evergreen montane forests in Ethiopia are severely *** status of species composition and structure of forest vegetation are important indicators to understand the trends of threats on local plant *** the present study,we examined the floristic composition and structure of the Kibate Forest,Wonchi Highland,Ethiopia along environmental ***-six(30 m×30 m)plots were established every 100 m interval along altitudinal gradients(2811‒3073 m a.s.l.)in five transect lines for vegetation and environmental data *** total,125 vascular plant species belonging to 104 genera and 52 families were *** species(14%)were endemic to Ethiopia and *** two most dominant families,Asteraceae(29 species)and Lamiaceae(eight species)accounted for 30%of the total number of *** highest number of species(54%)was *** major community types(viz.,Olinia rochetiana-Myrsine melanophloeos,Ilex mitis-Galiniera saxifraga,Erica arborea-Protea gaguedi,and Hagenia abyssinica-Juniperus procera)were *** highest species richness,evenness,diversity,and importance value index were in community types 2 and *** 82%of the species and all endemic taxa except five were recorded in these two community *** most dominant woody species were ***,***,Olea europaea ***,Myrica salicifolia,*** ***,and *** with different patterns of population *** results show that there was a weak correlation between species richness and *** findings confirm that environmental variables both with interactions(such as altitude)and without interactions(such as livestock grazing)significantly(p<0.05)affect species *** activities and overgrazing by livestock appear to be the main threat in community types 2 and *** management practices and conservation measures such as prohibiting forest clearing and overgrazing and planting indigenous trees through commu

关键词： Endemic species environmental gradient Floristic composition Kibate Forest Population structure Wonchi

Phylogenetic alpha and beta diversity in tropical tree assemblages along regionalscale environmental gradients in northwest South America

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Journal of Plant Ecology 2014年第2期7卷 145-153页

作者： Sebastián González-Caro María Natalia Umaña Esteban Álvarez Pablo R.Stevenson Nathan G.Swenson Ecosystem Services&Climate Change Lab Botanical Garden of MedellínMedellínAntioquia 050001Colombia Department of Plant Biology Michigan State UniversityEast LansingMI 48824USA Department of Ecology Universidad de AlcaláAlcaláMadrid 28801Spain Department of Biological Sciences Universidad de Los AndesBogotá7495Colombia

Aims environmental gradients are drivers of species diversity;however,we know relatively little about the evolutionary processes underlying these relationships.A potentially powerful approach to studying diversity gradients is to quantify the phylogenetic structure within and between assemblages arrayed along broad spatial and environmental ***,we evaluate the phylogenetic structure of plant assemblages along an environmental gradient with the expectation that the habitat specialization of entire lineages is an important evolutionary pattern influencing the structure of tree communities along environmental *** We evaluated the effect of several environmental variables on the phylogenetic structure of plant assemblages in 145 plots distributed in northwestern South America that cover a broad environmental *** phylogenetic alpha diversity was quantified for each plot and the phylogenetic beta diversity between each pair of plots was also *** the alpha and beta diversity measures were then related to spatial and environmental gradients in the study *** Findings We found that gradients in temperature and potential evapotranspiration have a strong relationship with the phylogenetic alpha diversity in our study system,with phylogenetic overdispersion in low temperatures and phylogenetic clustering at higher ***,the phylogenetic beta diversity between two plots increases with an increasing difference in temperature,whereas annual precipitation was not a significant predictor of community phylogenetic *** also found that the phylogenetic structure of the plots in our study system was related to the degree of seasonal flooding and seasonality in *** particular,more stressful environments such as dry forests and flooded forests showed phylogenetic ***,in contrast with previous studies,we find that phylogenetic beta diversity was not strongly related to the spatial d

关键词： phylogenetic conservatism habitat filtering immigration environmental gradient

Taxonomic dependency and spatial heterogeneity in assembly mechanisms of bacteria across complex coastal waters

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Ecological Processes 2024年第1期13卷 80-97页

作者： Huizhen Yan Dandan Lin Gaoke Gu Yujie Huang Xuya Hu Zhenhao Yu Dandi Hou Demin Zhang Barbara J.Campbell Kai Wang State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products School of Marine SciencesNingbo University Key Laboratory of Marine Biotechnology of Zhejiang Province School of Marine Sciences Ningbo University Department of Biological Sciences Clemson University

Background Understanding community assembly mechanisms across taxa and space is fundamental for microbial ecology. However, the variability and determinants of assembly processes over taxa and space remain unclear. Here, we investigated taxonomic dependency and spatial heterogeneity in bacterial assembly mechanisms across coastal waters in the East China Sea using neutral and null models with customized visualization *** Overall, bacterial assembly mechanisms varied across broad taxonomic groups(phyla and proteobacterial classes) and space at the regional scale. A determinism–stochasticity balanced mechanism governed total bacterial assembly, while taxonomic dependency existed in assembly mechanisms and ecological processes. Among community ecological features, niche breadth and negative-to-positive cohesion ratio were strongly associated with the determinism-to-stochasticity ratio of bacterial groups. Bacterial assembly mechanisms commonly exhibited spatial heterogeneity, the extent and determinants of which varied across taxonomic groups. Spatial assembly of total bacteria was directly driven by many environmental factors and potential interactions between taxa, but not directly by geographic factors. Overall, the bacterial groups with higher spatial heterogeneity in assembly mechanisms were more related to environmental and/or geographic factors(except Bacteroidetes), while those with lower heterogeneity were more related to ecological *** Our results confirm the pervasiveness of taxonomic dependency and spatial heterogeneity in bacterial assembly, providing a finer understanding about regulation across complex coastal waters.

关键词： Bacterioplankton Assembly mechanism Niche breadth Null model environmental gradient Biogeography

Positive Interactions： Crucial Organizers in a Plant Community

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Journal of Integrative Plant Biology 2006年第2期48卷 128-136页

作者： Dong-Liang Cheng Gen-Xuan Wang Bao-Ming Chen Xiao-Ping Wei Key Laboratory of Arid and Grassland Agroecology at Lanzhou University Ministry of Education Lanzhou 730000 China College of Life Sciences Zhejiang University Hangzhou 310027 China

For more than a century, ecologists have concentrated on competition as a crucial process for community organization. However, more recent experimental investigations have uncovered the striking Influence of positive Interactions on the organization of plant communities. Complex combinations of competition and positive interactions operating simultaneously among plant species seem to be widespread In nature. In the present paper, we reviewed the mechanism and ecological importance of positive Interactions In plant communities, emphasizing the certainties and uncertainties that have made It an attractive area of research. Positive Interactions, or facilitation, occur when one species enhances the survival, growth, or richness of another. The Importance of facilitation in plant organization increases with ablotlc stress and the relative Importance of competition decreases. Only by combining plant interactions and the many fields of biology can we fully understand how and when the positive Interactions occur.

关键词： competition environmental gradient facilitation plant community plant-plant communications positive interactions.

Variation in seed traits and seedling vigour of Cordia africana *** in Ethiopia

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Journal of Forestry Research 2017年第5期28卷 925-934页

作者： Abayneh Derero Genene Tesfaye Zewdie Woldemariam Ethiopian Environment and Forest Research Institute

Cordia africana is a very important indigenous tree species for timber and other products and services in Ethiopia. Seed traits and seedling vigour of seeds from 12 provenances of the species were compared. Mean seed mass for each provenance was assessed for 1000 seeds in 10 replications, and seed length and width were measured for 100 seeds in four replications per provenance. Germination was assessed in a glasshouse taking 400 seeds from each provenance. Root collar diameter and height of 440 seedlings grown in a nursery for 290 days in Addis Ababa were measured. Seed length, seed width, seed mass, and shoot height and root collar diameter of seedlings showed significant differences (P environmental variables revealed significant positive correlations between seed width and germination percentage, seed width and altitude, seed width and longitude and seed length and latitude. Negative correlations were obtained between seed width and temperature, seed width and rainfall, seed mass and temperature, and germination and temperature of the seed source. As expected, differences in seed trait did not explain the variability in seedling vigour. Determining quantitative variations in seed traits and seedling vigour among provenances and the patterns along environmental gradients are essential for informing decisions on the tree improvement programme of the species.

关键词： Clinal Correlation environmental gradient Improvement Quantitative

Scale dependence of plant species richness and vegetation-environment relationship along a gradient of dune stabilization in Horqin Sandy Land, Northern China

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Journal of Arid Land 2014年第3期6卷 334-342页

作者： XiaoAn ZUO ShaoKun WANG XueYong ZHAO Jie LIAN Naiman Desertification Research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Laboratory of Stress Ecophysiology and Biotechnology Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Ecological patterns and processes in dune ecosystems have been a research focus in recent years, however the information on how dune stabilization influences the spatial scale dependence of plant diversity is still lacking. In this study, we measured the plant species richness, soil properties and altitude across four spatial scales （1, 10, 100 and 1,000 m2） at three different dune stabilization stages （mobile dune, semi-fixed dune and fixed dune） in Horqin Sandy Land, Northern China. We also examined the relationships between plant species richness, community composition and environmental factors along the gradient of dune stabilization. Our results showed that plant species richness increased with the increase of spatial scales in each dune stabilization stage, as well as with the increase of dune stabilization degrees. Canonical correspondence analysis （CCA） showed that plant distribu- tions in the processes of dune stabilization were determined by the combined environmental gradient in relation to soil organic carbon （SOC）, total nitrogen （TN）, carbon/nitrogen （C/N）, pH, electrical conductivity （EC）, soil water content （SWC）, fine sand （FS）, very fine sand （VFS）, silt and clay （SC）, and altitude. Plant species richness was significantly and positively correlated to SOC and TN in mobile dune, and significantly and positively correlated to SOC, TN, C/N, VFS and SC in semi-fixed dune. However, no significant correlation between plant species richness and environmental factors was observed in fixed dune. In addition, plant species richness in different dune stabili- zation stages was also determined by the combined gradient of soil properties and altitude. These results suggest that plant species richness has obvious scale dependence along the gradient of dune stabilization. Soil resources depending on dune habitats and environmental gradients caused by dune stabilization are important factors to de- termine the scale dependence of species diversity in sand dune eco

关键词： CCA environmental gradient sandy land ecosystem spatial scale dependence species diversity

Are phylogenies resolved at the genus level appropriate for studies on phylogenetic structure of species assemblages?

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Plant Diversity 2021年第4期43卷 255-263页

作者： Hong Qian Yi Jin Research and Collections Center Illinois State Museum1011 East Ash StreetSpringfieldIL62703USA Key Laboratory of State Forestry Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China Guizhou Normal UniversityGuiyang550025China

Phylogenies are essential to studies investigating the effect of evolutionary history on assembly of species in ecological communities and geographical and ecological patterns of phylogenetic structure of species *** phylogenies well resolved at the species level are lacking for many major groups of organisms such as vascular plants,researchers often generate a species-level phylogenies using a phylogeny well resolved at the genus level as a backbone and attaching species to their respective genera in the phylogeny as polytomies or by using a megaphylogeny well resolved at the genus level as a backbone and adding additional species to the megaphylogeny as polytomies of their respective ***,whether the result of a study using species-level phylogenies generated in these ways is robust,compared to that based on phylogenies fully resolved at the species level,has not been ***,we use 1093 angiosperm tree assemblages(each in a 110110 km quadrat)in North America as a model system to address this question,by examining six commonly used metrics of phylogenetic structure(phylogenetic diversity and phylogenetic relatedness)and six climate variables commonly used in *** results showed that(1)the scores of phylogenetic metrics derived from species-level phylogenies resolved at the genus level with species being attached to their respective genera as polytomies are very strongly or perfectly correlated to those derived from a phylogeny fully resolved at the species level(the mean of correlation coefficients is 0.973),and(2)the relationships between the scores of phylogenetic metrics and climate variables are consistent between the two sets of analyses based on the two types of *** study suggests that using species-level phylogenies resolved at the genus level with species being attached to their genera as polytomies is appropriate in studies exploring patterns of phylogenetic structure of species in ecological communities

关键词： Genus-level phylogeny Species-level phylogeny Phylogenetic diversity Phylogenetic relatedness Community phylogenetics environmental gradient

Tropical tree community composition and diversity variation along a volcanic elevation gradient

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Journal of Mountain Science 2022年第12期19卷 3475-3486页

作者： Ruben MARTINEZ-CAMILO Manuel MARTINEZ-MELENDEZ Nayely MARTINEZ-MIELENDEZ Derio Antonio JIMENEZ-LOPEZ Mauricio JOSE-RIOS Unidad Villa Corzo Facultad de IngenieríaUniversidad de Ciencias y Artes de Chiapas30520 Villa CorzoChiapasMexico Instituto de Ciencias Biológicas Universidad de Ciencias y Artes de Chiapas29039 Tuxtla GutiérrezChiapasMexico Eizia A.C. 29045 Tuxtla GutiérrezChiapasMexico Departamento de Conservación de la Biodiversidad El Colegio de la Frontera Sur29290 San Cristóbal de las CasasChiapasMexico Orquidiario y Jardín Botánico de Comitán Secretaría de Medio Ambiente e Historia Natural30106 Comitán de DomínguezChiapasMexico Instituto de Investigación en Gestión de Riesgos y Cambio Climático Universidad de Ciencias y Artes de Chiapas29039 Tuxtla GutiérrezChiapasMexico

Unraveling the factors that determine variation of diversity in tropical mountain systems is a topic for debate in plant *** is especially true in areas where topography is complex due to volcano elevational gradients and where forests are vulnerable to human *** this study we used a set of climatic(temperature,rainfall,and radiation solar),topographic(elevation,slope aspect,and slope orientation)and human disturbance variables to determine their effect on diversity and composition patterns of a tree community,considering three slope aspects of a tropical volcano in southeastern *** sampled trees in seventy 0.1-ha plots distributed on three slope aspects of the Tacanávolcano along an elevational gradient of 1500 to 2500 *** determined diversity patterns(general tree richness,exponential of Shannon index,and pioneer species richness)with linear regression models,and for beta diversity,we used a dissimilarity index(within and between elevational bands 100 m wide).The effect of a set of environmental and human disturbance variables on tree diversity and community composition was analyzed with general linear models and multivariate analyses,*** registered 2,949 individual trees belonging to 176 species and *** average species richness and alpha diversity per plot were 13(standard deviation±6)and 9(±5),*** tree richness and alpha diversity increased in the middle part(unimodal patterns)of the elevational gradient,but pioneer species richness decreased linearly with *** variance explained by general linear models was greater in richness(32%)than in alpha diversity(25.3%).The most important predictor variables were temperature(elevational gradient),which explained the unimodal pattern(richness and alpha diversity increase at intermediate levels of temperature),and slope orientation,which explained the increase in richness and alpha diversity toward the geographic *** temperature had a signific

关键词： Composition environmental gradient Tree diversity patterns Tropical humid cloud forest Tropical volcanoes